2,2-Dimethyl-4,7-dihydro-1,3-dioxepine

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To an ice-cold (5°), stirred solution of the dioxepin (II) (12.81 g, 0.1 mole) in aqueous t-butanol (50%; 50 ml) adjusted to pH 6.0 with dilute sulfuric acid, was added t-butyl hypochlorite (11.3 g, 0.105 mole), while the pH was maintained at 6.0. The reaction mixture was allowed to rise to room temperature and stirred for 4 hrs with protection from light. Sodium bisulfite (200 mg) was added to the reaction mixture, followed by 50% aqueous sodium hydroxide to bring the pH to 12. The reaction mixture was heated at 100° for 1 hr and then cooled. The upper t-butanol layer was separated and the aqueous layer was extracted with t-butanol (3×20 ml). The combined organic layers were dried (Na2CO3). Solvent removal, followed by fractional distillation, gave the epoxide product (III) as a colorless oil in ≃80% yield. while the pH was maintained at 6.0 to rise to room temperature The reaction mixture was heated at 100° for 1 hr cooled The upper t-butanol layer was separated the aqueous layer was extracted with t-butanol (3×20 ml) The combined organic layers were dried (Na2CO3) Solvent removal followed by fractional distillation

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a suspension of sodium carbonate (37 g, 0.35 mole) in a mixture of the dioxepin (II) (158.7 g, 1.26 mole), benzonitrile (127.9 g, 1.26 mole) and methanol (150 ml), was added 30% aqueous hydrogen peroxide (42.2 g, 1.24 mole) during 30 min at such a rate that the temperature stayed below 80°. The mixture was kept at 80° with an oil bath for 2 hr, by which time 99% of the hydrogen peroxide added had reacted. The mixture was decanted and, then, subjected to fractional distillation first at 60 mm, then at 20 mm and finally at 6 mm. The fraction boiling at 75°-85° at 6 mm was refractionated at 6 mm to obtain the product (III) as a colorless liquid. (125.5 g) (70% yield). b.p. 82°-87°/6 mm. stayed below 80° added had reacted The mixture was decanted subjected to fractional distillation first at 60 mm

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred solution of 2,2-dimethyl-4,7-dihydro-1,3-dioxepin (151.4 g, 1.18 mole) in methanol (500 ml) was added anhydrous sodium carbonate (85 g), followed by acetonitrile (150 ml). This suspension was treated with aqueous hydrogen peroxide (30%; 315 ml, 2.78 mole) dropwise at such a rate that the temperature was maintained at 40°. After 5 hr. at 40°, the reaction mixture was poured into brine (1.5 l) and the solution was extracted with n-butanol. The organic layer was washed with brine, dried, and, then, freed of the solvent in vacuo. Vacuum distillation of the residue yielded the product (III) as a colorless liquid (114 g) (67% yield). was maintained at 40° the solution was extracted with n-butanol The organic layer was washed with brine dried Vacuum distillation of the residue

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a suspension of m-chloroperbenzoic acid (74% pure; 78.15 g; 0.33 mole) in methylene chloride (600 ml), was added a solution of 2,2-dimethyl-4,7-dihydro-1,3-dioxepin (II) (41.0 g, 0.32 mole) in methylene chloride (200 ml) during 30 min at room temperature. The mixture was refluxed for 8 hrs and then cooled in ice for 1 hr. The precipitated solid was filtered off and the organic filtrate was washed with 10% aqueous sodium sulfite (2×100 ml), saturated aqueous sodium bicarbonate (3×500 ml), 5% aqueous sodium hydroxide (2×250 ml) and brine (2×200 ml) and dried (MgSO4). Removal of the solvent followed by vacuum distillation of the residual oil gave the epoxide product (III) as a colorless liquid. 36.94 g (80% yield). b.p. 90°-92°/11 mm. The mixture was refluxed for 8 hrs cooled in ice for 1 hr The precipitated solid was filtered off the organic filtrate was washed with 10% aqueous sodium sulfite (2×100 ml), saturated aqueous sodium bicarbonate (3×500 ml), 5% aqueous sodium hydroxide (2×250 ml) and brine (2×200 ml) dried (MgSO4) Removal of the solvent followed by vacuum distillation of the residual oil

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To an ice-cold (5°), stirred solution of the dioxepin (II) (12.81 g, 0.1 mole) in aqueous t-butanol (50%; 50 ml) adjusted to pH 6.0 with dilute sulfuric acid, was added t-butyl hypochlorite (11.3 g, 0.105 mole), while the pH was maintained at 6.0. The reaction mixture was allowed to rise to room temperature and stirred for 4 hrs with protection from light. Sodium bisulfite (200 mg) was added to the reaction mixture, followed by 50% aqueous sodium hydroxide to bring the pH to 12. The reaction mixture was heated at 100° for 1 hr and then cooled. The upper t-butanol layer was separated and the aqueous layer was extracted with t-butanol (3×20 ml). The combined organic layers were dried (Na2CO3). Solvent removal, followed by fractional distillation, gave the epoxide product (III) as a colorless oil in ≅80% yield. while the pH was maintained at 6.0 to rise to room temperature The reaction mixture was heated at 100° for 1 hr cooled The upper t-butanol layer was separated the aqueous layer was extracted with t-butanol (3×20 ml) The combined organic layers were dried (Na2CO3) Solvent removal followed by fractional distillation

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a suspension of sodium carbonate (37 g, 0.35 mole) in a mixture of the dioxepin (II) (158.7 g, 1.26 mole), benzonitrile (127.9 g, 1.26 mole) and methanol (150 ml), was added 30% aqueous hydrogen peroxide (42.2 g, 1.24 mole) during 30 min at such a rate that the temperature stayed below 80°. The mixture was kept at 80° with an oil bath for 2 hr, by which time 99% of the hydrogen peroxide added had reacted. The mixture was decanted and, then, subjected to fractional distillation first at 60 mm, then at 20 mm and finally at 6 mm. The fraction boiling at 75°-85° at 6 mm was refractionated at 6 mm to obtain the product (III) as a colorless liquid. (125.5 g) (70% yield). b.p. 82°-87°/6 mm. stayed below 80° added had reacted The mixture was decanted subjected to fractional distillation first at 60 mm

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred solution of 2,2-dimethyl-4,7-dihydro-1,3-dioxepin (151.4 g, 1.18 mole) in methanol (500 ml) was added anhydrous sodium carbonate (85 g), followed by acetonitrile (150 ml). This suspension was treated with aqueous hydrogen peroxide (30%; 315 ml, 2.78 mole) dropwise at such a rate that the temperature was maintained at 40°. After 5 hr. at 40°, the reaction mixture was poured into brine (1.5 l) and the solution was extracted with n-butanol. The organic layer was washed with brine, dried, and, then, freed of the solvent in vacuo. Vacuum distillation of the residue yielded the product (III) as a colorless liquid (114 g) (67% yield). was maintained at 40° the solution was extracted with n-butanol The organic layer was washed with brine dried Vacuum distillation of the residue

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a suspension of m-chloroperbenzoic acid (74% pure; 78.15 g; 0.33 mole) in methylene chloride (600 ml), was added a solution of 2,2-dimethyl-4,7-dihydro-1,3-dioxepin (II) (41.0 g, 0.32 mole) in methylene chloride (200 ml) during 30 min at room temperature. The mixture was refluxed for 8 hrs and then cooled in ice for 1 hr. The precipitated solid was filtered off and the organic filtrate was washed with 10% aqueous sodium sulfite (2×100 ml), saturated aqueous sodium bicarbonate (3×500 ml), 5% aqueous sodium hydroxide (2×250 ml) and brine (2×200 ml) and dried (MgSO4). Removal of the solvent followed by vacuum distillation of the residual oil gave the epoxide product (III) as a colorless liquid. 36.94 g (80% yield). b.p. 90°-92°/11 mm. The mixture was refluxed for 8 hrs cooled in ice for 1 hr The precipitated solid was filtered off the organic filtrate was washed with 10% aqueous sodium sulfite (2×100 ml), saturated aqueous sodium bicarbonate (3×500 ml), 5% aqueous sodium hydroxide (2×250 ml) and brine (2×200 ml) dried (MgSO4) Removal of the solvent followed by vacuum distillation of the residual oil